1. Field of the Invention
This invention relates to a method for restricting repeated reproduction of an information signal recorded on a recording medium, and the device of the same.
2. Description of the Related Art
Accompanying the widespread use of video tape recorders (hereunder, referred to as VTR), a lot of software that VTRs can reproduce has been provided. Recently, a digital VTR and a reproducing or recording/reproducing device of a DVD (digital video disc) have been available, and it becomes easy to enjoy videos and sounds of a high picture and sound quality.
On the other hand, however, these devices invite a risk that the readily supplied software is duplicated without restriction. Accordingly, a measure has been taken to prevent a duplication, in which a duplication prevention control is carried out by adding a duplication prevention control signal to control prohibition, permission, or generation restriction of a duplication on an information signal.
FIG. 1 illustrates a basic construction of a recording/reproducing device that deals with a video signal from a VTR, etc., on which a duplication prevention control signal is added, as the information signal. The recording/reproducing device shown in FIG. 1 is supplied with a video signal S11 on which a duplication prevention control signal reproduced, for example, by a reproducing VTR is added.
The video signal S11 having the duplication prevention control signal added thereon is supplied to a writing unit 11 and a duplication prevention control signal detecting unit 12. The writing unit 11 converts the video signal S11 into a video signal S12 for recording so as to record it on a recording medium. The writing unit 11 is controlled by a writing control signal S14 from a writing control unit 13.
The duplication prevention control signal detecting unit 12 detects a duplication prevention control signal added on the video signal S11. Here, the duplication prevention control signal detected is supplied to the writing control unit 13 as a duplication prevention control signal S13.
The writing control unit 13 generates the writing control signal S14 on the basis of the duplication prevention control signal S13 supplied thereto, and controls the writing of the video signal S11 by supplying the writing control signal S14 to the writing unit 11.
The writing unit 11 is designed to write the video signal S11 supplied in a recording medium 100 if the writing control signal S14 from the writing control unit 13 indicates permission of a duplication, and not to write the video signal S11 in the recording medium 100 if the writing control signal S14 indicates prohibition of a duplication.
Further, if the duplication prevention control signal S13 from the duplication prevention control signal detecting unit 12 indicates permission of a duplication only for the first generation, the writing control unit 13 supplies the writing unit 11 with the writing control signal S14 for instructing to permit a duplication and change the duplication prevention control signal S13 added on the video signal S11 into a signal that indicates prohibition of a duplication for the second generation and after.
In this case, the writing unit 11 changes the duplication prevention control signal S13 for the recording video signal S12 into a signal to instruct prohibition of a duplication, and records on the recording medium 100 the recording video signal S12 on which the duplication prevention control signal S13 thus changed is added. Therefore, the video signal S12 recorded on the recording medium 100 cannot be duplicated any further in this case.
And, a signal S15 obtained from the recording medium 100 by reproduction is supplied to a read-out unit 14, which generates a reproduced video signal S16. This reproduced video signal S16 is supplied, for example, to a monitor receiving set to observe.
In this manner, the addition of the duplication prevention control signal S13 on the video signal S11 makes it possible to perform the duplication prevention control of the video signal S11 in accordance with the duplication prevention control signal S13, and to reproduce and observe the video signal S12 recorded on the recording medium 100 as needed.
If the video signal has the duplication prevention control signal added thereon, it is possible to perform the duplication prevention control in accordance with the duplication prevention control signal added on the video signal. However, if the video signal permitted for a duplication is supplied to the recording/reproducing device shown in FIG. 1, it is naturally possible to duplicate the video signal on the recording medium 100, and it is possible to repeatedly reproduce the video signal that has been duplicated on the recording medium 100; and the video signal will be used permanently.
In this manner, if the video signal permitted for a duplication is recorded on the recording medium, repeated reproduction becomes possible, and a further duplication of the video signal recorded on the recording medium becomes possible. Or, by lending the recording medium having the video signal permitted for a duplication recorded thereon to another person, an unspecified number of users will be able to use the same video signal repeatedly without limit.
Thus, when a video signal permitted for a duplication is provided, this video signal is used by an unspecified number of users with a high possibility, whereby the provider of the video signal will be subjected to a disadvantage. To avoid this situation, as mentioned above, it is possible to prohibit the duplication itself by adding the duplication prevention control signal on the video signal provided. This measure, however, is not agreeable to users who receive the supply of video signals, because the users will be subjected to too much restriction on the duplication of the video signal.
The present invention has been made in view of the foregoing problems, and an object of the invention is to provide a method, device, and recording medium, whereby a provider of information signals such as video signals is able to appropriately restrict the use of the information signals provided.
The invention provides a method for restricting reproduction of an information signal, in which an information signal having reproduction restricting information added thereon is stored, the information signal stored is reproduced, the reproduction restricting information of the information signal is detected, and repeated reproduction of the information signal stored is restricted in accordance with the detection of the reproduction restricting information.
Thereby, the provider of an information signal adds the reproduction restricting information on the information signal to be provided, which will prevent a user from a permanent use, for example, that the user duplicates the provided information signal on a recording medium and reproduces it repeatedly. Further, it is possible to prevent an unspecified number of persons whom the provider of the information signal does not give the authentication from a fraudulent use of the concerned information signal, by lending the recording medium having the provided information signal duplicated thereon to another person and repeating duplication, and the like.
According to another aspect of the method for restricting reproduction of an information signal relating to the invention, an information signal on which reproduction restricting information and identification information for indicating to have reproduced specified information are added is stored, the information signal stored is reproduced, the reproduction restricting information and the identification information of the information signal are detected, and repeated reproduction of the information signal stored is restricted in accordance with the detection of the reproduction restricting information.
Therefore, if the identification information is added, for example, at one position directly before the information finally read out of the information signal, since the obtained information signal is normally read out sequentially from the top, only with the read-out of the leading part of the concerned information signal, the foregoing identification information will not be detected; and therefore, the concerned information signal will not be erased. However, if the concerned information signal is read out to the last and used, the foregoing identification information is detected; and in this manner, if the foregoing identification information is detected, a repeated use of the concerned information signal can be restricted.
Further, the identification information may be a start information and an end information for indicating that a specified length of interval is read out, which are added on separate positions in time of the foregoing information signal.
Thereby, repeated reproduction of the concerned information signal cannot be restricted, if only a part of the concerned information signal is read out which does not include both the foregoing start information and the foregoing end information. If at least the whole information during an interval of which the start position and the end position are determined by the foregoing start information and the foregoing end information is read out and used, the use of the concerned information is identified to be ended, whereby the use of the concerned information can be restricted.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.